New photos recently emerged of China’s KJ-500 airborne early-warning and control plane. It’s Beijing’s fifth unique fixed-wing AEW&C aircraft. Which is kind of a big deal.

While hardly glamorous, these all-seeing planes are incredibly important to any modern air force. They transmit instructions and data — such as the presence of enemy fighters — with their powerful radars and sensors. If an air-to-air battle was an office, AEW&C planes would be the managers.

An air force with one of these planes in the air can see far more — and at much longer ranges — than an enemy without one.

But by any measure, five different types of AEW&Cs is a lot.

The KJ-500’s introduction also raises the question — just how many various kinds of airborne surveillance aircraft does an air force need?

The U.S. Air Force has a single aircraft of this type in service. Boeing’s E-3 Sentry has been operational since 1976, and remains the global standard for AEW&C planes. The U.S. Navy has the carrier-launched E-2 Hawkeye.

However, Beijing’s five different spies in the sky are not a symbol of one-upmanship. China may be increasing its year-by-year defense spending, but a bigger reason why it needs yet another AEW&C aircraft is because they’re really hard to build.

While military commanders and air power advocates often stress the vital importance of AEW&C to any modern-day air campaign, the process of refining the required hardware is beyond all but the most technologically advanced nations.

Russia has long struggled to field a truly effective airborne early-warning plane. India has been trying for years — without a tangible result.

If you have the money, and want the capability, the options are to buy from Israel or Sweden — two established, and innovative, players in the field of military electronics. Or, if you are politically acceptable in Washington’s eyes, you can choose the American option.

And if you’re China, you can constantly test new versions you mostly build yourself.

Above — China’s biggest AEW&C aircraft to date, only a handful of KJ-2000s have entered service with the Chinese air force’s 26th Division. At top — China’s latest AEW&C plane, the KJ-500, in February 2015. All photos via Chinese Internet

Beginnings

To be sure, Beijing has tried some of the other options. China first attempted to join the elite AEW&C club back in the mid-1960s. But until recently, its efforts were repeatedly frustrated.

In the early 1970s, Beijing outfitted a Soviet-supplied Tu-4 bomber as its first-generation AEW&C aircraft. But the modified warplane’s KJ-1 radar was a failure. It’s not even certain that the radar ever flew aboard the adapted Tu-4, which ended its days as a museum piece in the Chinese capital.

During the 1990s, the People’s Liberation Army looked toward Israel as a supplier of a working AEW&C system. The Israeli option looked good on paper — Israeli AEW&C systems are currently in use with the Chilean, Indian, Singaporean and Israeli air forces.

Even better, China wouldn’t even need to design a new airplane. In the airborne early-warning world, it’s the mission avionics — the centerpiece of which is a long-range airborne radar — which are at the heart of the system.

While the platform that carries this equipment isn’t exactly an afterthought, a number of different airliners and military transports — as long as they have the requisite load-carrying ability and internal dimensions — should fit the job.

China opted for the Soviet-era Il-76 airlifter as its platform for the planned Israeli electronics. It was an obvious choice in many ways, as the Il-76 was already a proven basis for AEW&C aircraft.

In the meantime, however, Washington stepped in and put a stop to the Sino-Israeli cooperation. An Il-76 airframe already delivered to Russia for the upgrade work had its Israeli-installed equipment stripped out.

China went back to the drawing board, and assigned top priority to the development of an AEW&C aircraft based on the Il-76.

But this new plane would incorporate indigenously-produced radar and mission avionics. The result was the KJ-2000, an aircraft based around the Type 88 early-warning radar.

Carried in a dish mounted atop the fuselage of the jet, the Type 88 doesn’t rotate like the familiar rotodome on the U.S. E-3. Instead, it carries three active electronically scanned antennas that provide 360-degree radar coverage.

The KJ-2000 may very well be the most capable AEW&C aircraft in the Chinese military. But China only built four of them since its introduction in 2005.

The reason for the KJ-2000’s limited numbers? A lack of airframes. China doesn’t build the Il-76 itself. Instead, Beijing bought most of these planes from Russia and Uzbekistan. But when Moscow put a stop to further Il-76 sales to China, and the KJ-2000 program apparently ground to a halt, too.

Since the embargo, China has acquired additional Il-76s from third-party sources. But to date, none have reemerged as an upgraded KJ-2000.

China is working on a new jet airlifter in the class of the Il-76, the Y-20. But it’s still in the early phases of its flight testing, and any possible AEW&C derivatives remain a long way off.

Another option is modifying no fewer than three different variants of the Y-8 four-turboprop transport, and its much-modernized Y-9 version.

Both of these transports have their roots in the Soviet Antonov An-12, a venerable machine first flown in 1957, and which remains in active service as a freighter in many parts of the world.

The enigmatic Y-8J was the first of Beijing’s AEW&C aircraft to enter service

Y-8J

Even then, China has plenty of existing AEW&C aircraft. But the first of these mid-sized planes remains something of an anomaly. It’s also somewhat weird looking.

Indeed, experts are still not exactly sure what role the Y-8J plays. But we’re certain that the PLA’s naval air arm operates it, and that the plane carries a British-supplied radar.

The Y-8J might also provide evidence that China’s naval air arm originally took the AEW&C mission more seriously than its land-based counterpart.

In the mid-1990s, London supplied Beijing with around eight examples of its Racal Skymaster radar, apparently in the belief that China would employ it for operations against illegal maritime traffic. That is to say, for civilian purposes.

Wrong. Instead, some of these Skymasters found their way onto navy-operated Y-8 transports, to produce the Y-8J variant.

It’s possible that China tasks these aircraft with traditional AEW&C duties. This could include flying with a fighter controller on board, whose job is to direct interceptors to engage aerial targets that the Y-8J has detected, identified and prioritized.

Another possibility is that Y-8J could direct over-the-horizon anti-shipping strikes, while working in concert with missile-toting helicopters. Either way, the enigmatic Y-8J clearly has a military role.

One of the Y-8J’s downsides is that it carries its primary surveillance radar in a grotesquely enlarged nose radome. This shape necessarily reduces the sector that its radar can scan.

The KJ-200 with its distinct balance beam radar array is in service with the Chinese navy

KJ-200

If the Y-8J relies on a bulbous nose, the KH-200 employs a very different arrangement. Developed during the second half of the 1990s under a project known as Gao Xin, the KJ-200 carries its electronically scanned phased-array antennas on a canoe-shaped fairing above the fuselage.

Known as “balance beam,” Sweden’s Ericsson first employed this same strut-mounted approach on its popular Erieye AEW&C system.

The KJ-200 — also known as the Y-8W — first flew in 2001. Since the balance beam layout doesn’t provide full-sector coverage on its own, the plane has additional antennas on its nose, wingtips, in the tip of the tail and atop the vertical fin.

The program suffered a blow with the loss of its second prototype in a fatal accident in 2006. But the KJ-200 is now in service with both the Chinese air force and naval air force — five and six airplanes in each, respectively.

While the KJ-200 has apparently provided a successful stopgap in the absence of further deliveries of the larger KJ-2000, further Chinese AEW&C developments using the Y-8 and Y-9 airframe has nonetheless continued.

The Chinese-made ZDK-03 is in service with the Pakistani air force

ZDK-03 and KJ-500

Here’s some of the newer ones. In the past few years, China produced another Y-8 variant with a rotodome, rather than a balance beam.

This design initially seems to have lost out against the rival KJ-200, so the rotodomed Y-8 continued to serve as a test vehicle with its Shaanxi-based manufacturer.

With China apparently uninterested in the aircraft, efforts switched to the export market. Beijing successfully sold the plane to Pakistan, where it’s known as the so-called ZDK-03 export variant.

Late last month, the Pakistani air force officially introduced the ZDK-03 to service, and renamed it the Karakorum Eagle.

The aircraft is now operating from Masroor, near Karachi. Intriguingly, Pakistani sources report that the range of aircraft’s Chinese-made radar exceeds that of Pakistan’s Swedish-supplied Erieye equipment, which it installed on Saab 2000 twin-turboprop plane.

There’s a few interesting things about it. For one, the original rotodome Y-8 had a rotating radome containing two antennas. This new plane has a fixed radome with three antennas — similar to its bigger brother, the KJ-2000.

Before the end of 2013, China had built at least two prototypes, and began testing them in Xi’an. In contrast to previous warplanes of the type, China based this new aircraft on the stretched — and much-improved — Y-9 airframe.

It remains to be seen what direction China’s airborne-control odyssey will go next. Beijing might have to give up the KJ-2000 if it can’t find any more airframes. The new KJ-500 could also supplant the earlier KJ-200 and its ungainly balance beam.

To top it off, two helicopter-based systems are now operational with the Chinese navy, which is developing its own fixed-wing, carrier-based model.

The one thing that looks certain is that Beijing hasn’t settled on a definitive solution to its airborne early-warning needs. With that in mind, it’s quite possible that Beijing’s busy military-industrial complex will yield a lot more AEW&C types in future.